This invention relates to material handling equipment and more particularly, to conveyor systems.
The invention is particularly applicable to a live guide system or rollerway in gravity type conveyors and will be described with particular reference thereto. However, it will be appreciated by those skilled in the art that the invention has broader applications and may be adapted for use in many different environments.
Gravity conveyors per se are well known in the art. While such conveyors may take many forms, one common type utilizes cylindrical rollers or wheels journalled between a pair of parallel spaced apart frame members at spaced intervals therealong for purposes of defining a conveyor section. Typically, a plurality of metal rollers are commonly journalled between the rails about axes which are normal or perpendicular to the rail lengths. A plurality of the conveyor sections may be disposed in end to end and/or side by side relationships so that the rollers or wheels define a flowpath along which loads, workpieces or the like may be conveyed from one area or work station to another. While the subject invention finds particular use in connection with the foregoing general type of gravity conveyor system, it will be appreciated that there are a number of other types and styles of such systems available. The broad concepts of the subject invention are deemed equally applicable to use in conjunction with or in place of the various alternative systems.
Because of the nature of the rollers employed in the foregoing conveyor systems, and in addition to the normal rolling relationship, loads travelling along a flowpath may experience a sliding relationship relative to the rollers. Such sliding is commonly referred to as walking and comprises movement of the load to one side or the other of the conveyor centerline. This walking is typically caused by a lack of conveyor levelness or improper alignment and may allow the load to travel off of the predetermined desired and/or safe path.
When loads are being moved along gravity type conveyors, it is oftentimes thus considered desirable, even necessary, to provide appropriate load guiding capabilities at the conveyor side edges. Heretofore, such guiding has oftentimes been effected by simply utilizing additional conveyor sections positioned adjacent and normal to the load bearing sections. Such arrangement adds undesired overall costs to the conveyor system since use of these additional conveyor sections overcompensates for the actual amount of guiding assistance typically required. Moreover, use of additional conveyor sections to provide side guiding often involves makeshift arrangements which are easily disturbed during actual use to cause disruptions in the conveying action.
Other types of makeshift guide arrangements have also been previously employed. These have similarly proved to be lacking in desired guide capabilities and flexibility of use. Furthermore, previously known conveyor guide arrangements have been stationary relative to loads conveyed therepassed. Such stationary mountings or relationships create friction between the load and guides thus reducing the effectiveness or efficiency of a gravity conveying action.
Another problem encountered with gravity type conveyors is one of load speed control. Typically, such conveyors do not include any means to effect speed control so that load speed along a flowpath is primarily a function of load size, initial load speed, condition of the conveyor rollers and flowpath conformation. Oftentimes, a combination of the foregoing factors in such that load speed is too high and beyond acceptable or safe limits. Here, too, prior efforts at providing some type of speed control means were primarily makeshift and directed to individual conditions.
It has, therefore, been considered desirable to develop an effective guide and speed control system for gravity type conveyors. The subject invention is believed to meet these needs while overcoming the foregoing problems and others to provide a new and improved live guide system or rollerway for gravity conveyors which is simple, effective, versatile, provides load speed control, is adapted to use in a wide variety of conveying applications and which may be employed in conjunction with conventional gravity conveyors, as part of conventional gravity conveyors or in place of such conveyors.